With the progressing of the technology, the touch display device is widely used in electric products, such as tablet personal computer and smart phone. In the conventional touch display device, a light with long wavelength is used as detecting light, and a plurality of light-detecting elements are used for receiving the detecting light reflected from a touch operating element into the display device through a color filter. Generally, the color filter includes a plurality of red photoresists, a plurality of blue photoresists and a plurality of green photoresists. However, according the current technique, there are only the red photoresists having the enough light transmittance with respect to the detecting light with long wavelength. Therefore, in order to increase the light intensity received by the light-detecting elements, the light-detecting elements are disposed to correspond to the red photoresists in the conventional touch display device. Accordingly, the amount of the light-detecting elements disposed in the conventional touch display device is limited by the arrangement of the light-detecting elements, so it is difficult to increase the photo-sensing resolution of the conventional touch display device.
In another conventional touch display device, the sensing areas of the light-detecting elements are enlarged for increasing the light intensity received thereby. However, the brightness and the color saturation of the touch display device would be decreased.